In a power equipment control system connected, via a communication network, to a system operation server of a power system and a single or a plurality of power equipments for performing power consumption or storage with interconnecting to the power system, to regulate power demand and supply balance of the power equipment, a contribution degree is obtained by preparing a demand plan of subsequent power of said power equipment; transmitting, to said power equipment, information relevant to demand regulation request to said power equipment, received from said system operation server, based on said demand plan; receiving demand regulation result of observation information on the demand regulation performed within said power equipment, based on said demand regulation request; and performing said demand regulation by said power equipment from said demand regulation result.